• 한국물환경학회지
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• 제36권1호
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• pp.36-47
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• 2020

Three large scale weirs were constructed 2010 - 2011 in the Namhan river, Korea. The purpose of this study was to investigate the spatial distribution of benthic macroinvertebrates and the influence of environmental factors at the weirs 2014 - 2015. The number of species was higher in the riparian zone than in the transition or the limnetic zone. This seems to be because of the diversification of microhabitats and food sources according to the development of littoral zones. From the riparian zone to the limnetic zone, the individual abundance proportion of gathering collectors among functional feeding groups decreased, and that of filtering collectors increased. In the limnetic zone, sprawlers and climbers among habitat orientation groups decreased, and burrowers increased. This means that coarse particulate organic matter originated from land or riparian zone was transformed to fine particulate organic matter in the limnetic zone. Asian clam (Corbicula fluminea) and chironomids were dominant species based on individual abundance. Asian clam, a major taxon considering biomass, was abundant toward the limnetic zone. This is becasue of the shallow depth, suitable water current, slightly coarse substrate, and good water quality. There was no significant relationship between the water quality and the characteristics of the benthic macroinvertebrate community because the water quality was spatially not heterogenous. The more influential factors for benthic community were physical factors, especially water depth. Water depth showed a markedly significant correlation with Shannon-Weaver's species diversity (r=-0.90), Margalef's species richness (r=-0.82), and McNaughton's dominance (r=0.86). Water depth showed a positive correlation (r=0.68) with the Kong and Kim BMSI (Bentic Macroinverebrates Streambed Index), and this may be related to the coarse substrate of the limnetic zone.

• Mycobiology
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• 제45권3호
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• pp.160-171
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• 2017

Larvae of Bradysia agrestis, an insect vector that transports plant pathogens, were sampled from geographically isolated regions in Korea to identify their cutaneous fungal and bacterial flora. Sampled areas were chosen within the distribution range of B. agrestis; each site was more than 91 km apart to ensure geographical segregation. We isolated 76 microbial (fungi and bacteria) strains (site 1, 29; site 2, 29; site 3, 18 strains) that were identified on the basis of morphological differences. Species identification was molecularly confirmed by determination of universal fungal internal transcribed spacer and bacterial 16S rRNA gene sequences in comparison to sequences in the EzTaxon database and the NCBI GenBank database, and their phylogenetic relationships were determined. The fungal isolates belonged to 2 phyla, 5 classes, and 7 genera; bacterial species belonged to 23 genera and 32 species. Microbial diversity differed significantly among the geographical groups with respect to Margalef's richness (3.9, 3.6, and 4.5), Menhinick's index (2.65, 2.46, and 3.30), Simpson's index (0.06, 0.12, and 0.01), and Shannon's index (2.50, 2.17, and 2.58). Although the microbial genera distribution or diversity values clearly varied among geographical groups, common genera were identified in all groups, including the fungal genus Cladosporium, and the bacterial genera Bacillus and Rhodococcus. According to classic principles of co-evolutionary relationship, these genera might have a closer association with their host insect vector B. agrestis than other genera identified. Some cutaneous bacterial genera (e.g., Pseudomonas) displaying weak interdependency with insect vectors may be hazardous to agricultural environments via mechanical transmission via B. agrestis. This study provides comprehensive information regarding the cutaneous microflora of B. agrestis, which can help in the control of such pests for crop management.

• 유기물자원화
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• 제26권4호
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• pp.31-43
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• 2018

본 연구는 유기 농경지의 토양 및 양분관리 방법으로 가축분과 풋거름(헤어리베치)공급, 윤작 시스템. 그리고 경운 및 무경운 처리가 토양환경에 미치는 영향을 구명하고자 수행하였다. 신규 옥수수 재배 토양의 양분공급원으로 가축분 퇴비, 헤어리베치와 같은 유기물 공급이 화학비료 처리에 비해 토양 유기물 함량을 높이며 토양의 미생물 밀도와 미생물체량 C함량을 증가시키는 것을 알 수 있었다. 또한 토양 미생물 군집의 기능적 다양성이 증가하는 것을 확인하였다. 윤작재배 효과로 토양 화학성은 처리간의 차이가 뚜렷하게 나타나지 않았지만 옥수수-밀, 옥수수-헤어리베치 윤작 처리구가 옥수수 단작 처리구보다 토양의 미생물체량 C 함량과 종 다양성 지수가 높은 경향을 보였다. 경운 여부에 따른 토양 화학성은 처리간의 뚜렷한 차이를 나타내지 않았다. 토양 미생물 군집의 기질 이용에서 무경운이 경운처리 보다 다소 높게 나타났지만 통계적인 유의차는 없었다. 처리에 따른 토양의 화학성과 미생물상간의 요인간 상관관계 분석 결과, 토양 유기물 함량과 치환성 칼륨 함량은 기질 이용도, 기질 풍부도와 양의 상관관계를 보였다. 이러한 결과로부터 가축분 퇴비, 헤어리베치와 같은 유기물 시용으로 옥수수 재배 토양의 화학성 및 미생물상에 긍정적인 효과를 나타낸 것으로 판단되었다.

• 한국산림과학회지
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• 제94권1호통권158호
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• pp.26-33
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• 2005

본 연구는 강원도 평창 지역의 천연 활엽수림을 대상으로 입지유형별 임분의 생장 특성과 생태적 특성을 구명함으로써 각 임분 특성에 맞는 산림관리 방안을 제시하고자 하였다. 이를 위해 연구 대상지를 방위, 해발고도, 지형 조건에 따라 36개의 입지유형으로 구분하고 각 입지유형별로 직경 생장량과 직경 생장률 그리고 Shannon-Wither의 다양성지수, 균재도, 풍부도를 파악하여 임분의 생장 특성과 생태적 특성을 비교 분석하였으며, 이를 근거로 산림관리 방안을 제시하였다. 임분의 생장 특성은 방위에 따라서는 동쪽 사면과 서쪽 사면이, 해발고도에 따라서는 서쪽 사면을 제외하고는 해발고도가 낮아짐에 따라, 그리고 지형 조건에 따라서는 사면과 계곡이 양호한 생장 상태를 유지하고 있었다. 생태적 특성은 적정한 습도 조건을 유지할 수 있는 지역으로 방위별로는 북쪽 사면과 서쪽 사면, 지형 조건별로는 계곡의 종 다양성이 높게 나타난 반면 해발고도에 따른 일정한 경향은 찾아볼 수 없었다. 입지유형별 산림관리 방안은 남쪽 사면과 동쪽 사면의 경우 임목 생장과 생태적 특성을 함께 고려한 무육작업이 필요한 반면 서쪽 사면과 북쪽 사면은 생장 촉진을 위주로 한 밀도조절이 필요한 것으로 파악되었다. 해발고도에 따라서는 저지대는 생태적 특성을 고려한 무육관리가 필요하며, 고지대와 중지대는 직경 생장률이 2% 미만인 지역에 대해서는 생장 촉진을 위한 무육작업이 시급한 것으로 나타났다. 한편 지형 조건에 따라서는 남쪽 사면의 중지대와 고지대를 제외하고는 계곡의 생태적 안정성이 기장 양호한 것으로 나타나 친환경적 경영에 가장 적합한 지역으로 평가되었다.

• 한국물환경학회지
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• 제34권1호
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• pp.84-95
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• 2018

The community structure of benthic macroinvertebrates in the fine sediments of freshwater was analyzed according to various sampling tools and methods. The sediment core with the inner diameter of 7.5 cm was more effective in cost and labor in comparison to that of ${\Phi}5cm$ or ${\Phi}10cm$. The number of species increased with the increase in sample size (replicates). When it was collected five times with the ${\Phi}7.5cm$ sediment core, Shannon-Weaver's diversity and McNaughton's dominance of the sample reached about the 80 % level of the community estimates. Most species appeared in the sediment layer of 0-4 cm, and there were no newly recruited species below the depth of 4 cm. Individual abundance of benthic macroinvertebrates decreased exponentially along with the increase in sediment depth. Compared with the individual abundance of the 0-15 cm sediment layer, the abundance was 60 % in the 0-2 cm layer, 25 % in the 2-4 cm layer, 10 % in the 4-6 cm layer and 95 % in the 0-6 cm layer. Compared with organisms collected with the sieve of 0.2 mm pore, the number of species and the individual abundance sifted through the sieve with pore of 1 mm were 36 % and 88 %, and those with pore of 0.5 mm were 5 % and 55 %, respectively.

• Journal of Animal Science and Technology
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• 제64권5호
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• pp.897-910
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• 2022

Bovine fecal microbiota is important for host health and its composition can be affected by various factors, such as diet, age, species, breed, regions, and environments. The objective of this study was to evaluate the impact of diet and gender on fecal microbiota in Korean native Hanwoo cattle. The 16S rRNA gene amplicon sequencing of fecal microbiota was conducted from 44 Hanwoo cattle divided into four groups: (1) 11 heifers fed an oat hay plus total mixed ration (TMR) diet for breeding (HOTB), (2) 11 heifers fed an early fattening TMR diet (HEFT), (3) 11 steers fed the early fattening TMR diet (SEFT), and (4) 11 steers fed the late fattening TMR diet (SLFT). Firmicutes and Bacteroidota were the first and second most dominant phyla in all the samples, respectively. The Firmicutes/Bacteroidota (F/B) ratio associated with feed efficiency was significantly greater in the SLFT group than in the other groups. At the genus level, Romboutsia, Paeniclostridium, and Turicibacter were the most abundant in the SLFT while Akkermansia, Bacteroides, and Monoglobus were the most abundant in the HOTB group. Although the same early fattening TMR diet was fed to Hanwoo heifers and steers, Marvinbryantia and Coprococcus were the most abundant in the HEFT group while Alistipes and Ruminococcus were the most abundant in the SEFT group. Shannon and Simpson diversity indices were significantly lower in the SLFT group than in the other groups. Distribution of fecal microbiota and functional genetic profiles were significantly different among the four treatment groups. The present study demonstrates that different diets and genders can affect fecal microbiota and the F/B ratio may be associated with feed efficiency in Hanwoo cattle. Our results may help develop strategies to improve gut health and productivity through manipulation of fecal microbiota using the appropriate diet considering Hanwoo cattle gender.

• 한국환경생태학회지
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• 제25권6호
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• pp.819-827
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• 2011

최근 범지구적 문제가 되고 있는 지구온난화와 이로 인한 서식처의 환경변화는 고위도 지방의 식물이나 고산식물의 생존에 중대한 문제가 되고 있다. 본 연구는 강원도 태백산맥 고산지대에 분포하는 환경부지정 멸종위기종인 한계령풀 10개 집단에 대해 서식지와 분포 특성을 조사하기 위해 수행되었다. 한계령풀은 고도 940m~1,350m 의 범위에 분포하였으며, 이는 온도기후적으로 온량지수 (WI) $53^{\circ}C{\cdot}month{\sim}WI\;75^{\circ}C{\cdot}month$에 해당하여 냉온대북부림대에 속한다. 이 종은 $5^{\circ}{\sim}23^{\circ}$ 경사의 북동사면에 주로 출현하였다. 한계령풀 분포지의 교목층은 신갈나무, 거제수나무, 층층나무, 고로쇠나무가 우점 하였으며, 관목층에는 고추나무, 물참대, 국수나무 등이 우점 하였다. 한계령풀 집단의 초본층 종다양도(Shannon's Index)는 0.21에서 0.98이며 각 집단에서 한계령풀의 중요치는 개화기에 가장 높은 값을 나타내었다. 서식지의 특성에 대한 본 연구는 한계령풀의 보전과 복원 전략의 수립 결정에 중요한 기초자료로 이용될 수 있을 것이다.

• 생명과학회지
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• 제24권4호
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• pp.461-466
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• 2014

본 연구에서는 독도에 자생하는 3종의 해안식물 해국(Aster sphathulifolius), 땅채송화(Sedum oryzifolium), 갯까치수영(Lysimachia mauritiana)을 연구 재료로 사용하였다. 각 식물에서 근권세균을 각 9주씩 분리하고, 동정하여 이들 세균의 다양성을 조사하고 근권 토양의 세균 집단 조성을 분석하였다. 16S rDNA의 염기서열 분석 결과, 계통학적으로 총 4문 19종의 근권세균이 분리, 동정, 확인되었다. 또한 본 실험을 통하여 독도 자생식물 근권 균주의 최적 생육 환경이 확인되었다. S. oryzifolium는 Rhodobacterales목, Micrococcales목, Corynebacteriales목, Flavobacteriales목, Oceanospirillales목, Bacillales목의 세균 균주가 확인되었으며, 자생식물 L. mauritiana에서는 Micrococcales목, Flavobacteriales목, Rhizobiales목, Oceanospirillales목, Rhodobacterales목, Bacillales목의 세균균주가 확인되었다. 자생식물 A. sphathulifolius에서는 Flavobacteriales목, Rhizobiales목, Corynebacteriales목, Micrococcales목, Alteromonadales목 및 Bacillales목의 균주가 분리, 동정, 확인되었다. 본 연구를 바탕으로 3종의 자생식물에서 방선균문(Actinobacteria)과 프로테오박테리아문(Proteobacteria)에 속하는 근권세균이 많이 존재함을 확인할 수 있었다.

• Animal Bioscience
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• 제34권9호
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• pp.1466-1478
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• 2021

Objective: Ruminants are completely dependent on their microbiota for rumen fermentation, feed digestion, and consequently, their metabolism for productivity. This study aimed to evaluate the rumen bacteria of lactating yaks with different milk protein yields, using high-throughput sequencing technology, in order to understand the influence of these bacteria on milk production. Methods: Yaks with similar high milk protein yield (high milk yield and high milk protein content, HH; n = 12) and low milk protein yield (low milk yield and low milk protein content, LL; n = 12) were randomly selected from 57 mid-lactation yaks. Ruminal contents were collected using an oral stomach tube from the 24 yaks selected. High-throughput sequencing of bacterial 16S rRNA gene was used. Results: Ruminal ammonia N, total volatile fatty acids, acetate, propionate, and isobutyrate concentrations were found to be higher in HH than LL yaks. Community richness (Chao 1 index) and diversity indices (Shannon index) of rumen microbiota were higher in LL than HH yaks. Relative abundances of the Bacteroidetes and Tenericutes phyla in the rumen fluid were significantly increased in HH than LL yaks, but significantly decreased for Firmicutes. Relative abundances of the Succiniclasticum, Butyrivibrio 2, Prevotella 1, and Prevotellaceae UCG-001 genera in the rumen fluid of HH yaks was significantly increased, but significantly decreased for Christensenellaceae R-7 group and Coprococcus 1. Principal coordinates analysis on unweighted UniFrac distances revealed that the bacterial community structure of rumen differed between yaks with high and low milk protein yields. Furthermore, rumen microbiota were functionally enriched in relation to transporters, ABC transporters, ribosome, and urine metabolism, and also significantly altered in HH and LL yaks. Conclusion: We observed significant differences in the composition, diversity, fermentation product concentrations, and function of ruminal microorganisms between yaks with high and low milk protein yields, suggesting the potential influence of rumen microbiota on milk protein yield in yaks. A deeper understanding of this process may allow future modulation of the rumen microbiome for improved agricultural yield through bacterial community design.

• 한국환경과학회지
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• 제12권6호
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• pp.573-582
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• 2003

According to the survey map, the altitudes of up and down the Ansungchon were 242m and 49m accordingly. The width of the river was 4m at upperstream and became wider, lam at midstream and 114m at downstream. Water pH of the Ansungchon was measured variously in the range of 6.0-7.9 according to the surveyed times and areas. The water pH measured during June through August decreased continually and suddenly increased at the end of October. Phragmites iaponica, a major species of the fresh water emergent anchored hydrophytes, was surveyed mostly in the area of upperstream, Phragmites communis, Miscanthus sacchariflorus and Typha orientalis were surveyed in the areas of midstream and downstream, and Zizania latifolia was found in all areas of the river. The total of 101 taxa dividing into 32 families, 71 genera, 88 species, and 13 varieties have been inhabited in these areas. Among the inhabited plants, Poaceae was 21.8%, which appeared in the highest percent. Compositae was 20.8%, and Polygonaceae was 11.9%. In the surveyed areas, herbaceous plants were 95.1% and mostly occupied, and woody plants were 4.9％. Among the herbaceous plants, perennial plants were 52.5%, and annual and biannual plants were 28.7% and 13.9% accordingly. Naturalized plants dividing into 8 families and 18 genera have been found in the surveyed areas. The number of the naturalized plants increased from upperstream to downstream as the environmental disruption became worse. Only 2.5% of the total naturalized plants were appeared in up, 17.7% in midstream, and 28.6% in downstream. Shannon-Weiner's index for the degree of diversity was 2.898-3.666 in the area of upperstream, but 3.708-4.135 in downstream, which was little higher.